To use the linearUpwind scheme you have to specify also a gradient scheme. The correct syntax in OF-2.0.x should be (for instance):

div(phi,k) Gauss linearUpwind grad(k);

where grad(k) is the scheme specified for k in the gradSchemes section (in your case, the default cellLimited leastSquares 1 scheme will be selected).
In OF-1.7.x this syntax will not be recognized, because you have to specify explicitly the gradient scheme, like in the following example:

div(phi,k) Gauss linearUpwind cellLimited leastSquares 1;

Finally, just a note about div(tauMC): it is an explicitly calculated divergence term, not a convective flux term, thus the only scheme that makes sense is Gauss linear.

Actually this syntax makes no sense, because the first order upwind scheme does not need any gradient scheme specification (I think that the code will simply ignore anything you write after "upwind"). Anyway, I advice you to use something more accurate for the reconcstruction schemes, like for instance:

And now I try find the scheme which will raise accuracy of the decision.

Thanks.

It depends from what you are looking for: rhoCentralFoam is designed as a transonic shock-capturing solver and the solution scheme of Tadmor and Kurganov is also constructed for this kind of flows, so using a first order scheme in my opinion introduces too much diffusion. I've noticed that sometimes rhoCentralFoam returns an oscillating behavior, but if you set the gradientScheme to a limited option (as for instance the cellLimited leastSquares 1 option) the oscillations are largely smeared out. It's up to you.